1. Technical Field
The disclosure relates to a hybrid vehicle and a control method for a hybrid vehicle.
2. Description of Related Art
A hybrid vehicle in which three rotation elements of a planetary gear mechanism are respectively connected to an engine, a first motor, and a second motor, in which the rotation element, to which the second motor is connected, is connected to a driveshaft via a stepped transmission, and in which the driveshaft is coupled to wheels has conventionally been proposed (for example, see Japanese Patent Application Publication No. 2014-144659 (JP 2014-144659 A)). Driving of the hybrid vehicle is basically controlled as follows. First, requested drive power is set on the basis of an accelerator pedal operation amount by a driver and a vehicle speed. Requested power that should be output from the engine is computed by multiplying the requested drive power by a rotational speed of the driveshaft. Next, a target speed of the engine is set on the basis of the requested power and an operation line of the engine on which fuel economy becomes optimum (a fuel economy optimum operation line). Then, the engine, the first motor, the second motor, and the stepped transmission are controlled so as to travel while the engine rotates at the target speed to output the requested power and the requested drive power is output to the driveshaft.